Echinoderma. 299 



EcMiioderma. 



776) Bather, F. A., On Cydonocrinus parvulus, n. g. et sp. , a fossil crinoid 

 from the Yoredale Beds, Yorkshire. In: Ann. and Mag. Nat. Hist., Vol. 12, 

 S. 388—394, 6 Textfig., 1913. 



Besides describing Cydocrinus, the author gives a careful revision of the characters 

 of the family, Taxocrinidae, to which Cyäocrinus belongs. Saunders. 



777) Bather, F. A., Caradocian Cystidea from Girvan. In: Trans, of 

 R. Soc. Edinburgh, Vol. XLIX, S. 359 — 529, 6 Taf., 80 Textfig., 1913. 



Though written in order to describe Girvan material, this memoir has grown 

 to little less than a monograph of the genera dealt with and even includes the 

 description of a new form from Bohemia. The class Cystidea as defined by 

 Bather excludes the Edrioasteroidea, but excludes forms that have been removed 

 from the Cystidea by Haeckel as Amphoridea and by Jaekel as Carpoidea. 



The author retains provisionally the order Amphoridea. The class Carpoidea 

 of Jaekel is rejected but its order Heterostolea is retained and rediagnosed as 

 a sub-order of Amphoridea. The genus Bliipklocysüs is discussed and thought 

 to be synonymous with Plaiycysütes S. A. Miller. A new family Cothurnocystidae 

 is established for the reception of the new genus Cothurnocijsüs with its two 

 species, C. el'izae and curvata. The order Rhombifera is discussed and its content 

 compared with Jaekel's order Dichoporita. Any attempt to split up the Rhombi- 

 fera into suborders, such as Jaekel's Regularia and Irregularia, is dismissed as 

 impracticable. The genus Cheirocrinus receives a fresh diagnosis. The treatment 

 of Pleuroci/stis only comes short of being monographic because there was not 

 time to study the actual type specimens of the American species. Its genotype 

 is held to P. squaniosa. The American species are then revised and re-diagnosed, 

 while the British species are diagnosed and fully described. 



Turning to details of anatomy we find many additions to previous knowledge. 

 The previously very brief description of RJüpidocystis is supplemented by fresh 

 details. In Cofhurnocysfis we have introduced an entirely novel plan of Echinoderm 

 structure. Here it will be enough to mention the existence of fifteen or more 

 separate openings into the gullet. Each of these may be regarded as a mouth; 

 they are not comparable to the numerous arm passages in Camerate Crinoids, 

 all of which lead to a Single subtegminal mouth. Both in Cheirocrinus and Pleuro- 

 cystis fresh material has enabled the plates to homologised with greater accuracy 

 and confidence. 



Taken as a whole the Cystidea of the Starfish Bed, teil as that we have 

 to account for immigration from Bohemia on the one side and from Canada on 

 the other, while we must not exclude some connection with the north -eastern 

 Baltic. The author concludes this monograph with some interesting speculations 

 on the adaptations of the Cystidea to the life they led and the bearing of these 

 adaptations of the evolution of the various types. Saunders. 



778) Hawkins, Herbert L., The Anterior Ambulacrum ot EcJiinocardium 

 cordatum Penn., and the Origin of Compound Plates in Echinoids. 

 In: Proc. Zool. Soc. London, Pt. II, S. 169—181, 1 Taf. and 3 Textfig., 1913, 



The author describes a new method for exposing sutures in dried specimens 

 of Echinoids. The dried test is brushed over with a Solution of some aniline dye, 

 which stains deeply the organic matter that remains between the sutures. The 

 dye is washed off and the surface is next brushed over with hydrochloric acid. 

 The effect of the acid is to remove all the external granulation and markings 



